Container for compressed gases and liquids



1934- c. w. JOHNSTON CONTAINER FOR COMPRESSED GASES AND LIQUIDS Filed Sept. 10, 1932 a z 4 w J U2 3 r. MW 3 .WMJIWE J J v J F latented Dec. 18, 1934 UNITED STATES PATENT, OFFICE CONTAINER FOR COMPRESSED GASES AND LIQUIDS Charles Wiswell Johnston, Portsmouth, Va. Application September 10, 1932, Serial No. 632,595

10 Claims. :1. 221-735) This invention relates to containers for compressed gases and, liquids and more particularly I sequently withdrawn for use without. escape or loss of the gas by the attachment of a suitable valve controlling mechanism thereto.

An important feature of the present invention resides in the simple manner of constructing the containers from two substantially hemispherical shells welded together at their meeting edges.

Another important feature of the invention resides in the provision of a container for compressed or liquefied gases having a discharge spud with a self-contained valve therein, together with a discharge and valve operating mechanism adapted to be applied over the spud to operate the valve and to restrain and direct the delivery of the discharged gases.

Still another important feature of the invention resides in the provision of a discharge spud for gas containers having therein a loose valve member to cooperate with the discharge passage therethrough and a plug for locking the valve in position.

A further feature of the invention resides in the provision of a safety means which may comprise a fusible plug directly in the valve member.

A still further important feature of the invention resides in the provision of a casing adapted to be secured onto the spud and to include a rod adapted to engage said plug to release the valve, and in which casing is provided a discharge passage through which the escaping gases are directed. p

Another important feature of the invention resides in the provision of means to prevent the extraction of the plug and hence of the valve so that the container cannot be refilled except by destroying a portion of the valve mechanism.

Other and important features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawing and following specification, wherein is disclosed the single exemplary em-- bodiment of the invention, with the understanding, however, thatsuch changes and variations may be made therein as fall within the scope of the appended claims.

In said drawing: Figure 1 is a central section through a container and valve mechanism constructed according to "the present invention, showing the valve closed;

Figure 2 is an enlarged fragmentary view of the valve mechanism showing the valve in open position;

Figure 3 is a transverse section on line 3-3 of Figure 1 showing the locking means for the valve plug; and I Figure 4 is a perspective View of the valve member or cone.

In the transportation and storage of compressed or liquefied gases (which are usually either irritating, such as sulphur dioxide, chlorine, or ammonia or inflammable such as petroleum, and in any case may be the cause of convalve is then closed, and the container with its valve is shipped to the desired destination. In

order to insure against damage to the valve, which usually projects beyond the end of the cylinder and consequently forms a particularly vulnerable part of the whole apparatus, the Interstate Commerce Commission now requires that the valve .mechanism of such containers shall be protected by a cap or the'like while in transit.

It is. also required that the containers shall [be provided with a suitable safety device. In

practice the safety'device has heretofore been either a frangible disc on the body of the container or in the valve which will rupture if the pressure in the container becomes excessive or a fusible plug that will melt if the container is overheated 'to a point where the pressure therein would become dangerous.

The present practice involves an unusually large investment in cylinders and in valves and caps for the" cylinders whichare in transit and storage, and this is especially great when the individual containers are small because of the increased number of valves per unit volume of gas. Furthermore, this practice incurs a considerable expense by increasing the weight and volume of the containers, thus increasing the transportation charges both when filled and returned empty.

The cylinders are so expensive that they must be used many times, and they are often refilled by others than those who make the product shipped in them. In the case of liquid sulphur dioxide, for example, this sulphur dioxide must be not only very pure but absolutely clean, dry, and free from all dirt. It is most difiicult to clean cylinders, and in practice it often happens that sulphur dioxide, for example, charged into small cylinders by others than the manufacturers of sulphur dioxide, is ruined because the small cylinders were not absolutely clean. Therefore, it is very desirable to have a cylinder that is so cheap it would not be used a second time, and also it would be desirable to have a means for making even the expensive cylinder so that it could not be refilled except at a point where it could be properly handled, everything considered. The present invention not only reduces the actual weight of the container itself but lowers its cost to a point where it can be used but once and discarded. Full safety is provided by adequate means forvdischarge of the gas in case of excessive temperatures or pressures and in which the necessary mechanism for withdrawing the gases can be applied by the user and need not be shipped back and forth with the container.

Referring now to the drawing, there is disclosed at 10 the substantially spherical container for the compressed or liquefied gases. It is preferably formed of metal of only sufiicient thickness to meet the specifications of the Interstate Ccmn erce Commission to thus stand the maximum pressure which will occur therein by virtue of the normal temperature attained by the gas. Being spherical permits a minimum thickness to meet these specifications. Conveniently, this container is formed of an upper hemispherical pressed metal shell 11 and a corresponding lower hemispherical shell 12. These shells may be formed of any suitable material, for instance steel, and treated interiorly and exteriorly for the prevention of rust, corrosion, or the like in any well-known manner. The two shells are secured together by welding as at 14 along their meeting edges to form the gas-tight container. One of the shells is provided with an outlet spud 15 preferably attached at its center by passing through an opening 16 in the shell and being welded thereto as at 17. This outlet spud is in the form of a cylinder of metal having a fiat outer end 18. It is provided with a small, central, longitudinal bore 20 forming the gas discharge passage and with a larger counterbore 21 extending from this passage to the outer end of the plug.

At the junction of the bore and counterbore there is provided a tapered passage 22 or valve seat into which loosely fits the valve member, or cone 24, best shown in Figure 4 as comprising a slightly truncated cone of any suitable metal having its conical surface tapered at the same angle as the valve seat 22 and preferably ground to the seat to insure gas tightness. It is truncated as at 25, leaving its lower end of about the same diameter as the gas passage 20. Longitudinally it is drilled as at 26 from end to end and filled with suitable fusible metal having a melting point such that the gas will be released when the temperatlu'e of this valve reaches a point where the pressure within the container would be dangerous. To provide both for the passage of gas from the bore holding the fusible metal and for the reception of a tool to grind the valve into its seat, a lateral kerf 27 is provided in the base 28 of the valve so that no matter whether the plug, to be later described, is pressing against the base or not, the gas can escape through this kerf to the sides of the valve.

The counterbore 21 is internally threaded as shown to receive the threads on the outer surface of the separate valve operating plug 30 which is of such a length that, when screwed in until its lower end 31 engages the base of the valve and holds it tightly on the seat, the outer end 32 is substantially flush with the outer end 18 of the spud.

The lower end of the counterbore is undercut or enlarged as at 35 to provide a shoulder 36 at the lower end of the threads in the counterbore. Extending from this shoulder to the outer end of the spud and beside the counterbore is a series of small passages 38 through which gas can flow either when the plug is partially unscrewed to allow the valve to unseat or in the event of melting of the fusible element, the gas then passing through the passage 20, the bore 26, the kerf 27, the enlargement 35 of the counterbore, and the passages 38 to the end of the spud.

In order that the valve may be proof against refilling, the inner portion of the plug is provided with a circular channel to into which is fitted a spring ring 41, the size of which is such that, when compressed, its outer diameter is no greater than that of the base of the threads in the plug so that, with the ring compressed, the plug can be screwed into place, but when the ring passes beyond the shoulder 36, it automatically expands and forms a permanent lock, forever preventing removal of the plug from the spud While the ring remains intact. This is an important provision since, with the aid of the separate valve cone, it prevents unauthorized persons from refilling the containers with sub-standard gases or with improperly purified and cleaned gases, as previously mentioned. Furthermore, the expansion ring prevents the plug from blowing out as might ordinarily happen if it were unscrewed too far by an inexperienced person.

The present container is so cheap that it does not need refilling and is proof against refilling by unauthorized persons. The loose, small, lightweight valve part is so constructed that any attempt to force gas, either compressed or liquefied, into the container immediately presses this valve against its seat so that substantially nothing can be put into the container. The valve is so light in weight that even if the container is placed .upside down so that gravity tends to hold the valve off of its seat, it is blown back on the seat by the gases attempting to enter.

With the plug 30 tightly screwed into position, the container is in condition for shipment, is provided with the required safety device, and has but a very small protruding spud which is of such adequate strength that it need not be protected by a cap, although a small pipe cap can be applied if desired. The spud and its cap add but little to the volume and weight of the container and thus effect a great saving in freight and in the space required for shipment and storage.

In order to be able to withdraw the contents of the container, a valve plug operating mechanism is provided. It includes a gas-tight casing of substantially cylindrical form having the enlarged end 51 interiorly threaded as at 52 to fit over the tapered pipe threads on the exterior of the spud. This type of joint can be made gastight with little difiiculty and without the use of packing. A lateral port 53 from the casing is threaded internally and externally as at 54 for the reception of a conductor tube for withdrawing the gas or liquid so that it can be drawn off without wasting or admixture withair. A valve plug operating rod 55 extends through and out of the upper end of the casing and is suitably packed as at 56 to permit it to have both rotational and longitudinal movement in the casing. At its outer end it is provided with any means to permit it to be rotated, such as a suitable hantile 60 and interiorly with a flange 5'7 to prevent its complete withdrawal through the packing. The inner end of this stem is provided with a suitable non-circular portion 58 to cooperate with a correspondingly shaped recess 59 in the upper end of the plug 30.

When the discharge casing is applied to the spud, the handle 60 is pressed inwardly and manipulateduntil the end 58 of the stem engages in the recess in the plug when, by turning the handle, the plug can be partially unscrewed, giving control-of the valveifor regulating the rate of discharge or for closing the valve to stop the discharge. The user need be provided with only the number of valve operating devices required to be in use at one time, whereas there may be hundreds of containers of gas in transit or storage for him. This materially reduces the investment necessary in valve mechanisms, and since the safety valve parts in the spud are extremely simple, the containers can be thrown away if desired because of their relatively low cost. a

If it is desired to refill the containers, authorized persons can, by drilling longitudinally of the plug a hole slightly larger than the minimum diameter at the channel 40, release the lower end of the plug as well as the ring 41 so that the upper portion of the plug can be withdrawn. Then, by the application of the proper tool, the ring can be engaged and withdrawn, after which the lower unthreaded end of the plug can be shaken out. A new plug after filling the container will provide for further use. It will, of course, be understood that the cylinders are filled with liquefied gas which has previously been cooled below its boiling point so that the liquid can be poured in and then the valve and plug applied without difliculty.

Hav'mg thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. The combination with a container for compressed or liquefied gases, of an outlet spud irremovably secured thereto and having a bore and counterbore communicating with the interior of the container, a valve seat between said bores, a valve member adapted to cooperate with said seat to close said bore, a plug having threaded engagement with the walls of said counterbore and adapted to press the valve onto its seat, and means to prevent the complete removal of said plug, said valve member being unattached so that pressure of entering fluid automatically seats it.

2. The combination with a container for compressed or liquefied gases, of an outlet spud secured thereto and having a small bore communicating with the interior of the container and a large counterbore extending to the end of the spud, said counterbore having an enlargement at its junction with the bore, a valve seat between said enlargement and bore, a loose valve member for said seat, a plug having threaded engagement with the walls of the counterbore and adapted to press the valve onto its seat, and means on said plug to expand into said enlargement when the plug is screwed into the counterbore to pre vent its complete withdrawal.

3. The combination with a container for compressed or liquefied gases, of an outlet spud secured thereto and having a small bore comrmmieating with the interior of the container and a large counterbore extending to the end of the spud, said counterbore having an enlargement at its junction with the bore, a valve seat between said enlargement and bore, a loose valve member for said seat, a plug having threaded engagement with the walls of the counterbore and adapted to press the valve onto its seat, means on said plug to expand into said enlargement when the plug is screwed into the counterbore to prevent its complete withdrawal, and an open gas passage from said valve to the end of said spud.

4. The combination with a container for compressed or liquefied gases, of an outlet spud secured thereto and having a small bore communicating with the interior of the container and a large counterbore extending to the end of the spud, a valve seat between said counterbore and bore, a conical valve member for cooperation with said seat, a plug having threaded engagement with the walls of said counterbore and adapted to press the valve onto its seat, said valve having a fusible core registering with said bore, there being a lateral passage from said core into saidcounterboreand a passage from said counterbore to the outside of said spud.

5. The combination with a container for compressed or liquefied gases, of an outlet spud secured thereto and having a bore and counterbore communicating with the interior of the container, a valve seat between said bores, a loose valve member adapted to cooperate with said seat to close said bore, a plug having threaded engagement with the walls of said counterbore and adapted to press the valve onto its seat, means to prevent the complete removal of said plug, a casing adapted to have gas tight engagement with said spud and having a lateral outlet, a rod extending through said casing and rotatably and longitudinally movable in a wall thereof, and means on said rod to engage and operate said plug to permit the withdrawal of regulated quantities of gas from the container.

6. The combination with a container for compressed or liquefied gases, of an outlet spud secured thereto and externally threaded, said spud having a central bore communicating with said container and a counterbore extending to the outer end of the spud, a loose valve cone cooperating with a seat at the junction of the bore and counterbore, a plug having threaded engagement with the walls of the counterbore and adapted to engage said cone to close the container, a passage from the cone to the outer end of the spud, a casing for threaded engagement over said spud and having an outlet passage, a stem having a slidable, rotatable and gas-tight fit in a wall of said casing, and means thereon to engage said plug to control said valve.

7. The combination with a container for compressed or liquefied gases, of an outlet spud secured thereto and externally threaded, said spud having a central bore communicating with said container and a counterbore extending to the outer end of the spud, an undercut in said counterbore, a loose valve cone cooperating with a seat at the junction of the bore and counterbore, a plug having threaded engagement with the walls of the counterbore and adapted to engage said cone to close the container, means on said plug to expand into said undercut to prevent removal of the plug, a passage from the cone to the outer end of the spud, a casing for threaded engagement over said spud and having an outlet passage, a stem having a slidable, rotatable and gas-tight fit in a wall of said casing, and means thereon to engage said plug to control said valve.

8. The combination with a container for compressed or liquefied gases, of an outlet spud secured thereto and externally threaded, said spud having a central bore communicating with said container and a counterbore extending to the outer end of the spud, an enlargement of said counterbore at the bottom thereof providing a shoulder, a loose valve cone cooperating with a seat at the junction of the bore and counterbore, a plug having threaded engagement with the walls of the counterbo're and adapted to engage the base of said cone to close the bore, means on said plug to permanently expand beneath said shoulder to prevent removal of said plug, a passag-e from the undercut to the outer end of the spud, a casing for threaded engagement over said spud and having an outlet passage, a handled stem having sl-idable, rotatable and gas-tight lit in the wall of said casing opposite said bore,- and means on said stem to engage said plug for rotation thereof to control said valve. A

9. A container for compressed or liquefied gases comprising in combination, a pair of substantially hemispherical, metal shells, means welding the edges of said shells togetherto form a gastight chamber,- a spud irremovably attached to one of said shells, a normally closed non-refillable valve in said spud, and detachable valve operating means engaged over said spud.

10. A valve structure for a gas container comprising in combination, a spud, an unattached valve member in said spud, non -removable means engaging said spud to press the valve closed, and operating means for said means engageable over said spud and including a gas discharge port.

CHARLES WISWELL JOHNSTON. 

